Date of Award
Doctor of Philosophy
Lisa I. Muller
Richard W. Gerhold, Brad F. Miller, Dana J. Morin, Sheng-I Yang
Managing sustainable wildlife populations requires insight into population abundance and health. Since reintroduction, elk (Cervus canadensis) at the North Cumberland Wildlife Management Area (NCWMA) in Tennessee have shown marginal population growth using low-precision abundance estimates. Limited research investigating possible population limiting factors has occurred since evaluations conducted directly after translocation. To provide information necessary for effective population management, we estimated abundance, identified survival rates, and conducted mortality and health surveillance. Precise abundance estimates of eastern elk populations are challenging to obtain using traditional capture-recapture due to invasive handling of individuals and low detection in forested landscapes. Therefore, we used elk DNA from scat noninvasively collected in 2019 to genetically identify individuals using 16 microsatellites with sex determination and estimated abundance using a Huggins closed capture model. From 157 successfully genotyped fecal samples, we identified 85 individuals (64 females, 21 males). The abundance model estimated 159 elk (123 females, 36 males) with acceptable precision (coefficient of variation: 15.6%) and identified a female skewed sex ratio (1:5). To further investigate population status, we placed GPS collars on 29 elk (21 females, 8 males) during 2019 and 2020. We estimated annual survival rates using known-fate models and identified primary causes of death of collared elk from 2019 to 2022. We estimated an average yearly survival rate of 80.2% with primary causes of mortality including meningeal worm (Parelaphostrongylus tenuis) associated disease (n=3), poaching (n=1), vehicular collision (n=1), legal hunter harvest (n=1), and unknown due to carcass degradation (n=3). We used blood, feces, tissue, and ectoparasites collected during elk capture to further assess population health. We conducted surveillance for pathogens based on presence in the southeastern United States, potential causes of elk morbidity and mortality, agricultural animal risk, and/or zoonotic risk. Our surveillance identified the presence of pathogens with potential negative population implications including P. tenuis and Mycobacterium avium subspecies paratuberculosis (Johne’s disease). Our research provided precise abundance estimates, sex ratios, and increased understanding of influential parameters of elk population growth: survival and health. Identifying potential population limiting factors can aid in supporting data-based management strategies for the NCWMA elk population.
Kurth, Katherine, "Elk Abundance, Survival, and Health in the Cumberland Mountains of Tennessee. " PhD diss., University of Tennessee, 2022.